Aston Martin advice from Bamford Rose independent specialist

I come to you for an intractable problem for several months on my Aston, ie far too much wealth from 4,000 rpm. Synopsis: when crossing the tsc on the bench, it was found that a lot of power missing. After another test on another bench later, the problem remains the same, namely, from 4,000 rpm, wealth surged to dangerous proportions in the engine.

This morning, I remade the test Aston Riviera (see values ​​for control of pollution). There should be constant over a wide speed range (1,000 to 6,000 kinds of revolutions per minute) between 0 and 0.5. From 1000 to 3'0000 and some rpm, everything is perfect, from 4,000 rpm, the values ​​start to panic and the 6.5 to 7.5, more than 10 times the correct value. In summary, the engine is too rich from the famous 4,000 rpm. For information manager, we tested the two exhausts separately.

Were tested: ECU, intake, exhaust, cylinder compression, spark plugs, injectors, ignition coils. It is the lambda sensors, but there is no error code in the suitcase and the cataliseurs (which are 200 cells instead of the 600 original cells).

the car is passed to dyno and it only comes out 330 hp.

Any idea, I'm all ears!

Thank you!

Vincent

Hi.

From what I can understand your engine is low on power and running what you consider to be too much fuel?

If this is the situation, what is your lambda value at high rpm from the dyno power curve run?

Hi Mike, You guys are the reason I joined Pistonheads. Is there an easier way, that is, without taking or significantly loosening the rear bumper cover to remove the small left and right grilles under the rear bumper? A special tool or technique? My cars fit and finish are exceptional...I would hate to disturb it if it can be avoided. I want to change the diffuser appearance and function on this car.

From what I can understand your engine is low on power and running what you consider to be too much fuel?

If this is the situation, what is your lambda value at high rpm from the dyno power curve run?

Do you have any MIL / check engine lamp warnings?

Mike.

Thanks for your answer!

There is the ratio:

I have no lights or engine lamp on, even my mechanic Aston Martin did not find anything on his computer connected to my car. It's been several months since it hard and I really do not know what to do ....

Hi Mike, You guys are the reason I joined Pistonheads. Is there an easier way, that is, without taking or significantly loosening the rear bumper cover to remove the small left and right grilles under the rear bumper? A special tool or technique? My cars fit and finish are exceptional...I would hate to disturb it if it can be avoided. I want to change the diffuser appearance and function on this car.

Hi.I am happy you like what you see at Bamford Rose..!

Speaking from memory, the grilles are held on with push on barbed clips which you have to damage to get off and bolted to the diffuser. But I will check one of our cars tomorrow to properly answer your question.

Answers to your questions to follow in separate posts which outline the different routes to performance upgrade the V8 Vantage. Skip to the end if you just want the executive summary…! I thought the detail to get there was important to include though.

I Hope this info dispels some myths, saves some money from potentially buying ‘the emperors clothes’, and delivers a route to transform slightly lacklustre 4.3L Vantage performance into a… Supercar..!

The outline you give for each performance upgrade was exactly what I was searching for, and I have watched this debate unfold with great interest – thanks Mike.You have hit the nail exactly on the head – the car needs greater low end torque. Coming from V12 I really know this to be the case. It is my opinion modified cars loose value in the resale market but there is real possibility that the 4.3L converted to 4.7L Vantage increases resale value because your mod elevates the cars performance so significantly above the many other 4.3L’s in the marketplace.Its quite an elegant solution also, I take it that the car remains totally standard looking from the outside?Paul

It is my opinion modified cars loose value in the resale market but there is real possibility that the 4.3L converted to 4.7L Vantage increases resale value because your mod elevates the cars performance so significantly above the many other 4.3L’s in the marketplace.Its quite an elegant solution also, I take it that the car remains totally standard looking from the outside?Paul

Being devils advocate, why would modifying one way devalue a car but doing it another increase the value? Doesn't make sense really.The engine conversion is permanent but the other mods, exhaust and intake can be put back to the original. So you would get the standard trade in plus you could sell on the extra parts.

If you are significantly different datalog your commanded AFRs (via OBD2). Check for Engine temp, Air temp sensor problems.Check that Fuel pressure stays at 55psi across the board. Check air filters and MAF's for dirt. You should run 4 volts and 35lb of air. Doesn't hurt to give them a good clean.

I have no lights or engine lamp on, even my mechanic Aston Martin did not find anything on his computer connected to my car. It's been several months since it hard and I really do not know what to do ....

If you are able to look at OBDII port data, look at variable FADPT, this is the fuel adaption value learnt by the system to return lambda 1 (~14.65:1 AFR) in closed-loop conditions.

It would be my guess that the number would be around 1.05, meaning it is taking around 5% fuel out to maintain lambda 1 in closed-loop conditions. But, when the fuelling goes open loop (for maximum performance when you open the throttle fully), the adaptions are not always carried across with reliability from closed to open-loop conditions.So in this scenario, the reason the system might take 5% out, means it is now over fuelling by ~5%.The reason in most cases is the MAF meters themselves being out of tolerance (meaning they return a value which is either higher or lower than the actual airflow).This is not a problem, this is something expected from manufacturing.However, if the MAF meters measure higher airflow than is actually being consumed by the engine, open loop, when fuelling corrections are not reliably carried across, a higher than needed amount of fuel will be delivered than is actually needed-but this is normal and expected in these conditions.

If there was a blockage or dirt in the system, it would be pre MAF meters, meaning this would cause a measured, lower, airflow and the correct lower amount of fuel would be delivered.

In most cases, lean running is due to an air leak (post MAF meters), as un-metered air is additionally introduced to the fuel diluting the mixture. Whereas rich running is more to do with a higher than actual measurement of air, although injector leakage could also be the cause, amongst a few other quirky conditions.

Under no circumstances blow the MAF meters out with compressed air to clean them, they are very sensitive components.

I can not really make comment on the power result as I do not know the dyno in question, and can not be certain the results are reliable.

However, put the dyno result to one side; There are no problems you can report (fault codes / error states or any comments from technician) So what exactly do you think is wrong with this car? What made you go to dealer to check the car out?

I need a little more information to be of any further help, but the slightly rich fuel is of no immediate concern. Clearly you are running rich, and a small amount of power will be lost as a result. For this reason I test all MAF meters for my motorsport cars to ensure the exact and correct flow of air is being measured, this way I know that the car will not run rich, and if anything I prefer MAF meters which read low, as this will run the engine lean and produce more power. This attention to detail is needed in the motorsport world but will mean very little in road cars.

In reality, finding the inner workings of the EMS is unlikely, so answers to questions 3,4,5, 7 and 8 are more-or-less irrelevant.Re MAF - You could always try V12 MAF tubes as they are slightly larger in volume / diameter.Re injectors - Search Jag parts bin for greater flow rate parts, DBS good for 500 ish BHP at 3.8 barRe the other calibration questions you have, if you have control of your jumper ECU, then you are free to calibrate parameters as you see fit? no?

However, I would have thought the supplier of your equipment would have conducted these activities prior to sale?

Good luck.Mike.

Most Ford ECUs can me accessed if the right access strategy is known. I guess thats what I'm asking for. Car runs well now but extra fuel comes from additional injectors. Stock injectors still in place. Piggyback ECU modifies MAF so bigger maf could be added. I just feel that modding the stock PCM is a "cleaner" setup. Going completely Motec is another option but would require large investment of time and money. Independent testing at http://www.youtube.com/user/rmrmd1956#p/a/u/2/l4c_...

Most Ford ECUs can me accessed if the right access strategy is known. I guess thats what I'm asking for. Car runs well now but extra fuel comes from additional injectors. Stock injectors still in place. Piggyback ECU modifies MAF so bigger maf could be added. I just feel that modding the stock PCM is a "cleaner" setup. Going completely Motec is another option but would require large investment of time and money. Independent testing at http://www.youtube.com/user/rmrmd1956#p/a/u/2/l4c_...

From the original questions you ask I can guess the problems you have, and they will be problems which are insurmountable without the access you speak of. This is unfortunate as the driver will loose many features of the car such as traction control, and the kit will need to be developed around safety monitors and error state lamps which illuminate when a particular threshold is crossed - a difficult task as all market conditions and fuel grades would need to be tested to ensure reliability.

Clearly, the performance modification question / answer debate depends on the individual outcome required and budget available. For those that only want to improve the exhaust note, there are many options and personal preference on exhaust note and manufacturing quality will no doubt guide the choice made when seeking out a supplier.

For those who want to go a bit further with a few bolt-on parts (ECU Re-map, catalysts, sports silencer and air induction system parts), these will return small additional gains. But be aware, the perceived gain (noise) is often greater than the real gain (acceleration time). Regarding the exhaust system, the only significant performance gain is to be had by fitting new (4-1) manifolds together with the rest of the system (motorsport cats and sports silencer).

If you love the 4.3L Vantage but just want (significantly) better performance, simple, upgrade to 4.7L. But, take the cost of trading up from the cheapest 4.3L (say £38k) to the cheapest 4.7L (say £68k) = £30k… Not cheap…But by stringing some performance mods together, it is possible to achieve performance levels far in excess of the cheapest 4.7L for around half the difference of the trade-up cost….. How? By upgrading displacement and by fitting the complete performance upgrade exhaust system (new manifolds, catalysts and sports silencer).

Mike-Thanks for all of the intel.I have a 4.3L and have done the following: -Quicksilver SuperSport exhaust 3.5BHP? -AM Power upgrade 25BHP? -K&N Air filters ?

3 questions: 1)Does the AM power upgrade combine your options 3 and 4 above (exhaust manifold and air intake=25BHP?) 2)If I add 200 CELL Catalysts will I need to have another ECU tune to take full advantage of BHP increases? 3)Any additional HP gains from the K&N performance air filters I added?

Being devils advocate, why would modifying one way devalue a car but doing it another increase the value? Doesn't make sense really.The engine conversion is permanent but the other mods, exhaust and intake can be put back to the original. So you would get the standard trade in plus you could sell on the extra parts.

I see your point. yes - the car can always be returned back to standard. My point, not put very well - was that whilst the exhaust kit is relatively low cost option, the engine conversion is more of an investment. So I would want to see that reflected in the cars value. In my mind it should do, as when advertised against other 4.3 it would be billed as 4.7 performance. I think it was a recent issue of EVO I was reading, where someone wrote "what used car should I go for - A 911 or Aston?" The advice given was Aston on looks, image and how it makes you feel, even though Aston was slower. The article said go for the 4.7 if you can afford it, but if you cant, the 4.3 is still better than 911. Based on this a 4.3 upgraded to 4.7 should attract more value than standard a 4.3.

Most Ford ECUs can me accessed if the right access strategy is known. I guess thats what I'm asking for. Car runs well now but extra fuel comes from additional injectors. Stock injectors still in place. Piggyback ECU modifies MAF so bigger maf could be added. I just feel that modding the stock PCM is a "cleaner" setup. Going completely Motec is another option but would require large investment of time and money. Independent testing at http://www.youtube.com/user/rmrmd1956#p/a/u/2/l4c_...

From the original questions you ask I can guess the problems you have, and they will be problems which are insurmountable without the access you speak of. This is unfortunate as the driver will loose many features of the car such as traction control, and the kit will need to be developed around safety monitors and error state lamps which illuminate when a particular threshold is crossed - a difficult task as all market conditions and fuel grades would need to be tested to ensure reliability.

Mike-Thanks for all of the intel.I have a 4.3L and have done the following: -Quicksilver SuperSport exhaust 3.5BHP? -AM Power upgrade 25BHP? -K&N Air filters ?

3 questions: 1)Does the AM power upgrade combine your options 3 and 4 above (exhaust manifold and air intake=25BHP?) 2)If I add 200 CELL Catalysts will I need to have another ECU tune to take full advantage of BHP increases? 3)Any additional HP gains from the K&N performance air filters I added?

ThanksEric

Hi Eric.

Sports Silencer – Based on the industry standard relationship of power increase for backpressure reduction, then somewhere in the region of 3.5 to a maximum of 5BHP is the reality from silencer upgrade. This modification is all about the sound and performance perception, less about actual vehicle acceleration times.

The AM power upgrade is an airbox kit which reduces induction system losses, and is worth approx. 10BHP. Together with ignition maps optimised for 100 Octane super green fuel, and is also worth approx. 10BHP. So, if you run 100 Octane then + 20BHP if 97 or 95 then only + 10BHP

K+N air filters, above the AM airbox update will return very little additional gain. The better modification onward from AM power pack airbox would be to remove the air induction system altogether and fit air filters similar to N24 / GT4 race cars.

Therefore, a good estimate of your performance level with the modifications you mention would be in the region of 410BHP.

In answer to your questions;The AM power upgrade you have with the quicksilver silencer means that if you fitted option 3 (sports exhaust manifold), it would mean additional 15BHP.

The inclusion of sports catalysts would mean a further 10.5 BHP gain, and would not require fundamental ECU mods to achieve this, but would require checks and measures put in place to ensure no faulty MIL illumination.

This would mean that the sports exhaust manifolds and catalysts (+25.5BHP) could be combined with your current AM power upgrade, air filters and your current sports silencer (410BHP), to return approx. 435.5BHP.

The outline you give for each performance upgrade was exactly what I was searching for, and I have watched this debate unfold with great interest – thanks Mike.You have hit the nail exactly on the head – the car needs greater low end torque. Coming from V12 I really know this to be the case. It is my opinion modified cars loose value in the resale market but there is real possibility that the 4.3L converted to 4.7L Vantage increases resale value because your mod elevates the cars performance so significantly above the many other 4.3L’s in the marketplace.Its quite an elegant solution also, I take it that the car remains totally standard looking from the outside?Paul

Hi Paul

Yes. On the surface no matter what the modification, the car would appear totally standard.Some customers have requested to remove the Aston badges, slam panel badges and door plates for Bamford Rose badges like the horsepower badge which can be found here;http://www.bamfordrose.com/index.php?option=com_co...or display the Bamford Rose logo.

Sports Silencer – Based on the industry standard relationship of power increase for backpressure reduction, then somewhere in the region of 3.5 to a maximum of 5BHP is the reality from silencer upgrade. This modification is all about the sound and performance perception, less about actual vehicle acceleration times.

The AM power upgrade is an airbox kit which reduces induction system losses, and is worth approx. 10BHP. Together with ignition maps optimised for 100 Octane super green fuel, and is also worth approx. 10BHP. So, if you run 100 Octane then + 20BHP if 97 or 95 then only + 10BHP

K+N air filters, above the AM airbox update will return very little additional gain. The better modification onward from AM power pack airbox would be to remove the air induction system altogether and fit air filters similar to N24 / GT4 race cars.

Therefore, a good estimate of your performance level with the modifications you mention would be in the region of 410BHP.

In answer to your questions;The AM power upgrade you have with the quicksilver silencer means that if you fitted option 3 (sports exhaust manifold), it would mean additional 15BHP.

The inclusion of sports catalysts would mean a further 10.5 BHP gain, and would not require fundamental ECU mods to achieve this, but would require checks and measures put in place to ensure no faulty MIL illumination.

This would mean that the sports exhaust manifolds and catalysts (+25.5BHP) could be combined with your current AM power upgrade, air filters and your current sports silencer (410BHP), to return approx. 435.5BHP.

Hope this answers your questions.Mike.

Hi Mike-this is great, thanks.

The last question I have is where do I get the sports exhaust manifold? I spent some time on your website bout could not find it.

In response to several requests, here are some considerations to be made if contemplating pressure charging your V8. It must be stressed that this discussion concerns pressure charging in general, without specific reference to any supplier of such equipment.

Concern should be raised if suppliers of forced induction kits do not remove and strip the engine and rebuild with parts suitable to withstand additional loads, pressures and temperatures associated with forced induction engines. Specifically; pistons, rods, bearings, cooling system and calibration should be revised.

Piston; bulk metal piston crown temperature, cylinder pressure maximum and knock over pressure limits were signed-off by manufacturer, naturally aspirated, @ 89BHP per litre. A ‘CLAIMED’ peak power output of ~550 BHP from forced induction must mean that BMEP (brake mean effective pressure) has risen from ~12 to ~16 Bar. Using industry standard rules that chart combustion gas temperature and pressure rise per 1.0 bar BMEP, would indicate that elevated forced induction combustion temperatures and pressures are highly likely to exceed the in-built safety factor / margin the manufacturer engineered-in to prevent failures for application of the piston in the standard engine. This means that the risk for pressure failure (cracked piston) and holed piston is high. My feeling is that there are so few forced induction kits in the marketplace, and those few have been used so little, is the only reason there is not an epidemic of piston failures in engines fitted with forced induction kits.

Connecting rod; The first 1000 4.3L Vantage engines were built with steel (expensive and strong) connecting rods, from then onwards normal production utilised sintered connecting rods (cheaper and weaker but nonetheless fit for purpose). ~16 Bar / 540BHP forced induction cylinder pressures and temperatures on steel rod = probably OK, but nonetheless unproven. The same conditions sintered rods = failed rod and written-off block highly likely. Remember the comment so few being used so little..

Crank; The crankshaft is bulletproof, the OE supplier is top quality. Weak link is big-end bearings and the concern would be delamination of bearing surface material due to increased heat. This is because Forced Induction heat output to oil is significantly greater than naturally aspirated. The concern would be that at prolonged maximum engine speed / peak power operating conditions, the oil temperature and aeration levels rise to the point where film thicknesses in bearing journals might become compromised. Between 380 BHP V8 Vantage to near 500 BHP V12 Vantage, and between 450 BHP DB9 to 510BHP DBS, the factory upgraded the cooling system for capacity and performance for each model. So why when going from 380BHP to 540BHP is the cooling of the standard car retained and is deemed sufficient by those who supply Forced Induction kits? On the V8 vantage the oil temperature going into the engine is, say, 90 degrees C (after being cooled), and comes out at approx. 130. Bearings start to delaminate at approx. 150 degrees. So, under prolonged running conditions when the additional heat output of the Forced Induction engine pushes the inlet temp from 90 to 110 (a strong likelihood) – Game over.

Calibration; Lost features… DSC is lost (yes, no traction control with more power – go figure..!!??), perhaps ABS, perhaps security (alarm) and perhaps elements of the dashboard too. Some kits I have seen are better at retaining these features than others. Failure modes and detection / avoidance; Simple example, as far as I can see the failure mode for running out of water injection is that you will run out of fuel before running the water tank dry, ok as long as you remember to fill it up, blown-up engine if you don’t. Even if a light comes on to warn driver of low water level, the suppliers of these kits cannot talk to the original ECU, they cannot program revised ‘limp-home’ modes should error states occur. So in this example water runs dry but the engine can still be operated in a condition that would cause damage.Another example, and one which worries every manufacturer who produces cars with drive-by-wire throttle systems. Should an electronic error cause the throttle blade to snap open wide with no driver pedal demand input, the OE ECU will safely put the car into limp-home / shutdown mode. A third-party ECU will never have this same level of robustness / intelligence. There are some systems I have seen which run an additional ECU alongside the OE ECU, here there are problems of general calibration competency when a ‘jumper’ ECU is fitted or OE ECU is replaced; calibration of electrical and other loadings like aircon (put aircon on with full battery loading from electrical drain, will engine stall out on return to idle?). Cold starts; at low altitude, at high altitude, using poor volatility fuel (for that time you go on holiday and find nothing but crap fuel in a remote place).

Summary; I think I have done the so little used by so few line to death… so here is another example. When I finished working on BMW mini Cooper supercharged program, I watched an episode of Top Gear where two upgraded models were tested. The John Cooper S works kit survived several laps around the circuit and would last a lifetime in reality, as the engineering behind that upgrade kit was as robust as the original manufacturer. The other car (who I forget the name of the tuning company) blew-up without posting a lap time as the engine was pushed too far by people who didn’t know what they were doing.

I am sure this response will generate comments from those running pressure charged Vantages, and without doubt, to fit a blower and to even get the car driving means a lot of hard work. I am happy for any discussion surrounding this subject to take place here if you wish. But I guess the only way to really prove otherwise is simple – give me the car for an hour around Silverstone...!